Police powers are granted to states in the 10th Amendment to the U.S.
Constitution, which reserves to the states the rights and powers "not delegated
to the United States," which include protection of the welfare, safety,
health and even morals of the public. Police powers denotes the basis for
many regulatory subjects, such as licensing, inspection, zoning, safety
regulations, and working conditions as well as law enforcement. Police
powers may be used, for example to detain people or search things like
vehicle.

It is a general term that expresses the fundamental power vested in
every state to limit and regulate the exercise of private rights in the
interest of public health, public morals, public safety, and the general
welfare of the community. Governments have exercised police power to prohibit
the sale of liquor and cigarettes and gambling. Cities and towns have prohibited
the making of bricks in a town, the maintenance of livery stables, public
laundries, billboards, public garages, coal yards and slaughterhouses.